Outburst of the Recurrent Nova V745 Sco








AAVSO Special Notice #380

Reported outburst of the recurrent nova V745 Sco February 6, 2014

Rod Stubbings (observer code SRX; Tetoora Road, Victoria, Australia) reports an outburst of the recurrent nova V745 Sco (aka Nova Sco 1937). Stubbings reports the nova at a visual magnitude of 9.0 on 2014 February 6.694 UT (JD 2456695.194). He previously observed the field on 2014 February 5.696 and found the star fainter than 13.0, indicating that this outburst began within the past 24 hours. Confirmation is very
urgently requested, and follow-up observations of all types (visual, CCD and otherwise) are strongly encouraged.  This object is located in Scorpius and is currently a pre-dawn object.

V745 Sco is located at the following (J2000) coordinates:

        RA: 17 55 22.27 , Dec: -33 14 58.5

A comparison star sequence exists for V745 Sco, and may be obtained from
the AAVSO website via VSP:


Please promptly report all observations of this nova to the AAVSO via
our WebObs tool, using the name "V745 SCO".

This AAVSO Special Notice was prepared by M. Templeton.


AAVSO Alert Notice 496

Outburst of the recurrent nova V745 Sco
February 7, 2014

Event: Outburst of the recurrent nova V745 Sco

Discovery by: Rod Stubbings (Tetoora Road, VIC, Australia)

Discovery magnitude: 9.0 (visual)

Discovery date: 2014 February 6.694 UT

Coordinates:  R.A. 17 55 22.27   Dec. -33 14 58.5  (2000.0)

Observing Recommendations: This recurrent nova is fading quickly. Follow-up observations of all types (visual, CCD, DSLR) are strongly encouraged, as is spectroscopy. V745 Sco is currently a pre-dawn
object, posing an additional challenge. AAVSO Nova Section advisor Dr. Jeno Sokoloski (Columbia University) has requested as much photometry and spectroscopy as possible. Professional researchers
are planning multiwavelength observations for V745 Sco, and your observations will be extremely important for correlation of these multiwavelength data.

Outbursts of recurrent novae are relatively rare events. Each outburst is an opportunity to add to the study of the relationship between recurrent novae and the progenitors of Type-Ia supernovae, so the most complete coverage possible is important.

Dr. Bradley Schaefer (Louisiana State University) suggests that fast time-series of this nova may be useful to detect possible flaring activity as was observed during the outburst of U Scorpii in 2010.  He suggests that coincident time-series by multiple observers would be most useful for such a study, with a V-filter being preferred.

Observations reported to the AAVSO:
2013 Oct. 27.41528 UT, <13.3 (MTH, H. Matsuyama, Kanimbla, QLD, Australia);
28.42639, <12.8 (Matsuyama);
28.44375, <14.1 TG (KBJ, R. Kaufman, Bright, VIC, Australia);
29.44167, <14.1 TG (Kaufman);
2014 Jan. 12.73958, <12.7 TG (Kaufman);
Feb. 01.1, 13.98 I (MLF, L. Monard, Calitzdorp, South Africa, via cba-chat);
03.1, 13.78 I (Monard, via cba-chat);
05.696, <13.0 (SRX, R. Stubbings, Tetoora Road, VIC, Australia);
06.694, 9.0 (Stubbings);
06.745, 9.0 (CMQ, P. Camilleri, Warners Bay, Newcastle, NSW, Australia);
06.77330, 8.66 V +/-0.06 (OCN, S. O'Connor, St. Georges, Bermuda,
remotely using iTel17, Siding Spring, NSW, Australia);
06.77390, 9.46 B +/-0.07 (O'Connor, remotely);
06.77450, 7.98 R +/-0.05 (O'Connor, remotely);
07.102, 9.04 V (Monard, via cba-chat);
07.104, 7.40 I (Monard, via cba-chat);
07.34557, 9.483V +/-0.010 (HMB, J. Hambsch, Mol, Belgium, remotely
at San Pedro de Atacama, Chile);
07.35522, 9.485 V +/-0.010 (Hambsch, remotely);
07.36012, 9.490 V +/-0.009 (Hambsch, remotely);
07.36503, 9.520 V +/-0.008 (Hambsch, remotely);
07.37016, 9.515 V +/-0.009 (Hambsch, remotely);
07.37464, 9.508 V +/-0.008 (Hambsch, remotely);
07.38047, 9.549 V +/-0.008 (Hambsch, remotely);
07.38520, 9.563 V +/-0.008 (Hambsch, remotely);
07.76300, 10.07 V +/-0.03 (O'Connor, remotely);
07.76500, 8.91 R +/-0.09 (O'Connor, remotely);
07.76600, 8.15 I +/-0.01 (O'Connor, remotely);
07.80903, 10.1 (PEX, A. Pearce, Nedlands, W. Australia);
07.85833, 10.2 (Pearce);

Charts: Charts for V745 Sco may be created using the AAVSO Variable Star Plotter (VSP) at http://www.aavso.org/vsp.

Submit observations: Please submit observations to the AAVSO International Database using the name V745 SCO.

a. Initially announced in AAVSO Special Notice #380 (M. Templeton).

b. Confirmed by Steve O'Connor (OCN, St. Georges, Bermuda) and Paul Camilleri (CMQ, Warners Bay, Newcastle, NSW, Australia); see Observations above.

c. Previous outbursts occurred in 1937 and 1989. The 1937 outburst was detected in 1958 (in decline at magnitude 11.0 on 1937 May 11.1 UT; outburst had occurred within the previous 19 days) by Lukas
Plaut on plates taken by Hendrik van Gent at the Leiden Observatory; the object was announced as Nova Sco 1937 and later assigned the GCVS name V745 Sco. The 1989 outburst was detected on 1989 August
1.55 UT by Mati Morel (MMAT, Thornton, NSW, Australia) at visual magnitude 10.4 and in decline.

d. Dr. Bradley Schaefer (Louisiana State University) reports (2010ApJS..187..275S) in his comprehensive analysis of the 10 known galactic recurrent novae (including V745 Sco) that the median
interval between recurrent novae outbursts is 24 years. The interval since the 1989 outburst of V745 Sco is 24.10 years.

Congratulations to Rod Stubbings on his detection of the outburst of this difficult pre-dawn recurrent nova!

This AAVSO Alert Notice was prepared by Elizabeth O. Waagen.

Images obtained remotely by left Martin Mobberley and right Nick James